Laboratories often perform a variety of test procedures such as, for example, tests to determine the presence or identity of an etiological agent. Each test may include an analyte-specific reagent (e.g., an enzyme substrate, a nucleic acid primer or probe, an antibody, a monoclonal antibody, or a receptor) that can detect the presence of a particular microorganism in a sample.
Laboratory tests for etiological agents are frequently performed in individual containers (e.g., tubes or microtubes). Additionally, it is not uncommon to process a batch of tests at the same time to improve the efficiency of the laboratory operations. Because similar tests are often performed in identical-appearing tubes, the laboratory technicians use labels to distinguish tubes containing different sample materials and/or analyte-specific reagents.
Labels are routinely applied to reaction tubes to identify the contents of the tubes. The labels may be written on the tube or a corresponding cap. Permanent, waterproof ink is used to prevent the label from washing or rubbing off during handling. Alternatively, an adhesive label, bearing a description of the contents of the tube, is attached to the tube.
The labels often include a large amount of information related to the contents of the tube (e.g., sample identity, date, the type of test or reagent-specific analyte, the operator). Bar-code labels are used in some instances, so that a relatively large amount of information can be incorporated into a relatively small label.